Kernel: Fix TOCTOU in fstatvfs

In particular, fstatvfs used to assume that a file that was earlier
opened using some path will forever be at that path. This is wrong, and
in the meantime new mounts and new filesystems could take up the
filename or directories, leading to a completely inaccurate result.
This commit improves the situation:
- All filesystem information is now always accurate.
- The mount flags *might* be erroneously zero, if the custody for the
  open file is not available. I don't know when that might happen, but
  it is definitely not the typical case.

1 files changed, 1 insertions, 1 deletions

diff --git a/Kernel/Process.h b/Kernel/Process.h
index bb26b29d3c..c6e3ae6453 100644
--- a/Kernel/Process.h
+++ b/Kernel/Process.h
@@ -535,7 +535,7 @@ private:
     ErrorOr<void> do_exec(NonnullRefPtr<OpenFileDescription> main_program_description, NonnullOwnPtrVector<KString> arguments, NonnullOwnPtrVector<KString> environment, RefPtr<OpenFileDescription> interpreter_description, Thread*& new_main_thread, u32& prev_flags, const ElfW(Ehdr) & main_program_header);
     ErrorOr<FlatPtr> do_write(OpenFileDescription&, const UserOrKernelBuffer&, size_t);
 
-    ErrorOr<FlatPtr> do_statvfs(StringView path, statvfs* buf);
+    ErrorOr<FlatPtr> do_statvfs(FileSystem const& path, Custody const*, statvfs* buf);
 
     ErrorOr<RefPtr<OpenFileDescription>> find_elf_interpreter_for_executable(StringView path, ElfW(Ehdr) const& main_executable_header, size_t main_executable_header_size, size_t file_size);